Intrinsic flame-retardant epoxy resin as well as preparation method and application thereof

Abstract

The invention discloses intrinsic flame-retardant epoxy resin containing a phthalonitrile and Schiff base structure as well as a preparation method and application of the intrinsic flame-retardant epoxy resin, and belongs to the technical field of flame-retardant high polymer materials. The molecular structure of the intrinsic flame-retardant epoxy resin contains a phthalonitrile unit, a Schiff base unit and an epoxy functional group at the same time. The preparation method comprises the following steps: carrying out nucleophilic substitution reaction on nitro-containing phthalonitrile and aminophenol to obtain an intermediate, carrying out Schiff base condensation on the intermediate and dihydroxy benzaldehyde, and finally reacting with epoxy chloropropane to introduce an epoxy group. The resin combines the condensed phase charring effect of phthalonitrile and the gas phase flame retardant effect of Schiff base to generate a synergistic effect. When the flame retardant is used as intrinsic resin or an additive for an epoxy resin composition, a cured product has excellent flame retardant property when the flame retardant is used as the intrinsic resin. When being used as an auxiliary agent, the flame retardant can improve the flame retardancy and mechanical properties of the epoxy resin on the premise of keeping thermal properties, and has excellent flame retardant efficiency.